Resiliently biased pedestal key assembly

ABSTRACT

A side frame key assembly for a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame comprises angular key structure providing top and bottom keys movably mounted in the key opening of the side frame, the bottom key having a lever portion overlying a horizontal base portion of the frame and a locking spring releasably reacting between the side frame and the bottom key to bias the top and bottom keys into engagement with the side frame at top and bottom corner regions bordering the key opening.

United States Patent MacDonnell et a1.

14 1 Sept. 16, 1975 RESILIENTLY BIASED PEDESTAL KEY ASSEMBLY 8/1974 Wresch 105/221 K 10/1974 Hlinsky 105/221 K Primary ExaminerM Henson Wood, Jr. Assistant ExaminerHoward Beltran Attorney, Agent, or Firm.]. Patrick Cagney [73] Assignee: R. W. Mac Company, Crete, Ill.

[22] Filed: Aug. 27, 1974 [57] ABSTRACT [21] Appl. No.: 500,850 A side frame key assembly for a roller bearing unit mounted for relative vertical movement in a pedestaltype side frame comprises angular key structure pro- [52] 105,221 295/36 d viding top and bottom keys movably mounted in the key opening of the side frame, the bottom key having [511 f g 3 25 2 a lever portion overlying a horizontal base portion of [58] Field of earch 3 36 42 5 6 the frame and a locking spring releasably reacting be- 5/ tween the side frame and the bottom key to bias the top and bottom keys into engagement with the side [56] References cued frame at top and bottom corner regions bordering the UNITED STATES PATENTS key opening 1,748,209 2/1930 Couch 105/221 14 3,521,570 7/1970 Hasten, Jr. 105 221 K 6 Clams 6 Drawmg Figures I8 /9W 22D /7 :1 l 22 19R T I91 /.9F y ,1 y /4 230 .r 1 I l l I/ I! g l I X RESILIENTLY BIASED PEDESTAL KEY ASSEMBLY BACKGROUND OF THE INVENTION In the case of railway car trucks that include pedes tal-type side frames, it is conventional to provide a side frame key mounted on the side frame to project through a key opening for retaining the roller bearing unit against accidental escape in the event of a derailment. The conventional side frame key is a one-piece steel forging or casting bolted to a horizontal base portion of the side frame adjacent to the key opening. The mounting bolt arrangement is not dependable because the vibrations associated with normal operations frequently work the nut loose and allow the bolt to pop out. The key easily falls out once the bolt is gone.

The existing one-piece keys, even the keys with a top extension to engage above the key opening can only transmit the usual vertical loads into the base portion of the side frame. Such loads also act on the bolts. Thus, the high shock forces associated with a derailment either break the key or shear the head off its mounting bolt. In addition, the bolted keys are sometimes difficult to remove when required for maintenance purposes.

SUMMARY OF THE INVENTION In accordance with the present invention an improved side frame key assembly is provided for easier and more secure mounting on the side frame to solve the vibration problem, to transmit the high shock loads associated with a derailment directly into the side frame and to allow easy removability and replacement, thereby facilitating truck maintenance operations.

The improved key assembly comprises angular keying structure, freely movable in the key opening and having bottom keying means to fulcrum against a bottom corner portion bordering the key opening and top keying means for abutment against a top corner portion bordering the key opening, the bottom keying means has an inwardly projecting lever portion overlying the horizontal base portion of the frame and an outwardly projecting retainer portion bordering the lower peripneral region of the roller bearing unit, and locking spring means releasably reacting between the base of the side frame and the bottom keying means to bias the bottom keying means and top keying means into constant engagement with the bottom corner portion and top corner portion, respectively, of the key opening.

In the preferred embodiment, the top and bottom keying means are provided as separate pieces, each piece being of suitably heavy stock capable of handling high load forces. Load forces are transmitted through the bottom key directly into the base portion of the side frame and by fulcrum action of the bottom key some of the load is transmitted through the top key and into the side frame. The locking spring is not subjected to the load forces but acts to bias the keys into constant engagement with the side frame.

The bottom key has a mounting pocket to receive the top key in correct registry and to provide interlocking between the keys that positively prevents loss. The unique key interlock is effective to retain the parts against accidental escape even without the locking spring.

The side frame key assembly is arranged to be applied in the train yard the same as brake shoes or other yard type repairs, thus eliminating the expense of shopping the car as is now the case. Equally important is the fact that the problem of missing roller bearing keys should gradually be eliminated since key replacements can now be made as part of the train yard program.

Eliminating the need for mounting bolts reduces the installation labor both as respects applying the bolts and as respects removing or burning off the bolts when changing wheels.

The locking spring feature keeps the keys tightly locked at all times, positively protects against vibration effects and eliminates the need for special tools.

The strength of the preferred side frame key embodiment and the resilient mounting relationship achieved for parts that are easy to remove and replace and are protected by being located in the truck side column insure a long useful life.

Other features and advantages of the invention will be apparent from the following description and claims, and are illustrated in the accompanying drawings which show structure embodying features of the present invention and the principles thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings forming a part of the specification, and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a fragmentary, transverse sectional view, showing a conventional pedestal-type side frame and roller bearing unit in conjunction with a side frame key assembly of this invention employing a two-piece angular key structure.

FIG. 2 is an end view showing the key assembly in mounted position.

FIG. 3 is an exploded perspective view of the parts of the key assembly.

FIG. 4 is a transverse sectional view, similar to FIG. 1, showing a modified embodiment having a two-piece angular key structure.

FIG. 5 is an end view of the embodiment of FIG. 4.

FIG. 6 is a transverse sectional view similar to FIG. 1 showing an embodiment utilizing a one-piece angular key structure.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings a conventional railway car truck arrangement is shown as including a pedestaltype side frame designated generally at 10 which is supported on a roller bearing unit 11. The side frame has vertical pedestal walls flanking the roller bearing unit 11 and normally allowing relative vertical movement between the roller bearing unit and the side frame for accommodating disassembly. The side frame wall 12 has a conventional key opening 13 and is shown to terminate in a horizontal base portion 14 that is typically provided with a hole 15 for an anchor bolt such as is used with prior art type side frame keys.

The improved side frame key of this invention uses an angular keying structure 16 in conjunction with a locking spring 17. The keying structure is freely movable in the key opening 13 and has top and bottom keying means 18, 19, biased into constant engagement withtop and bottom corner portions 12T, 14B, respectively, bordering the key opening 13 of the side frame. The bottom keying means 19 is free to fulcrum on the bottom corner portion 14B.

Constant engagement of the keying means 18, 19, as provided by the action of the locking spring 17 insures that-the keying structure seats snugly in proper position in the key opening 13 in spite of numerous dimension and profile variances in the different key openings encountered. Load forces applied to the key structure in connection with its function of retaining the roller bearing unit 1 1 are distributed by fulcrum action of the bottom keying means 19, some of the load being transmitted directly into the outside bottom corner portion 14B and some of the load being transmitted through the top keying means into the inside top corner portion 12T.

It should be noted that the load distributing action of the angular keying structure is insured by the presence of the locking spring 17, which establishes constant key engagement at both the top and bottom corner locations; however, the locking spring is not itself subjected to the load forces.

In the illustrated embodiments, the locking spring 17 is in the form of a folded leaf spring consisting of a generally circularly bowed head 20, having a flat anvil portion 21 and a pair of generally parallel arms 22, 23, each arm having an intermediate convex detent portion 22D, 23D, the detent portion 23D of the lower arm seating in a socket 24 in the bottom keyingmeans 19. When the spring 17 is in place, as shown in FIG. 1, it is in a contracted state, with the arms 22, 23 relatively close together and being urged apart by the expansive action of the head. The arms, in acting to expand, apply a positive bias to keep the detent portions interlocked in the bolt hole and socket 24 and develop an angular moment to press the key assembly into engagement with the corner portions 12T and 148 as previously described.

During normal operating conditions the usual vibration effects encountered will not dislodge the spring 17 nor will the Spring allow vibrations to disengage the key assembly from contact with the side frame corner portions; thus, when load forces are applied, whether simultaneously with vibration effects or not, the key is in constant engagement and is effective to distribute the load to both corner regions 12T,,14B of the side frame.

While it is contemplated within the scope of this invention to utilize the locking spring 17 with angular keying structure of one-piece form, in the preferred embodiment shown and described herein for purposes of illustrative disclosure, the angular key structure is provided as two separate pieces 18, 19, each separate key being of suitably heavy stock capable of handling high load forces.

The bottom key 19 has a substantially plate-like, full length horizontal main wall 19M providing an inwardly projecting lever portion 19L overlying the base 14 of the side frame and an outwardly projecting retainer portion 19R bordering the lower peripheral region of the roller bearing unit 11 to prevent the roller bearing from dropping out of the pedestal window of the side frame. The bottom key may be of any configuration capable of acting as a fulcrum on the bottom corner 14B and suitable for casting or forging.

In the illustrated embodiment, the main wall 19M is provided with ribs 19F that flank the socket 24 to define a guideway for insertion and removal of the spring arms 22, 23. The ribs 19F extend full length of the main wall and are enlarged at the retainer region to present downwardly facing shoulders 19D and inwardly facing shoulders 191 that serve as the keying means that is to fulcrum on the bottom corner portion 148. The retainer region 19R is generally arcuate in side profile to provide a broad contact area in close clearance with the roller bearing unit. The lever portion 19L of the main crosswall has a beveled underface region 19W to define a wedge-like mouth that facilitates insertion of the locking spring 17. Finally, the bottom key 19 has an upwardly opening interlock pocket 19? located centrally in its upper face, the pocket extending outwardly of the key opening to an intermediate region of the retainer portion 19R and inwardly of the key opening to an intermediate region of the lever portion 19L.

The top key 18 includes a pair of depending side ribs 18F that seat in the interlock pocket 19? with limited clearance fore and aft to accomplish self adjusting positioning of the top key by the bottom key thereby allowing limited freedom for the top key to accommodate to the specific size and contour of the top corner portion 12T of the key opening. Typically, the interlock pocket 19P is 1 15/16 inches (min.) and the side ribs 18F are 178 inches (max. The top key 18 has an upwardly facing top shoulder 18U and an outwardly facing transverse shoulder 18T to engage the top corner portion 12T.

It should be noted that the limited clearance mounting of the top key in the pocket of the bottom'key provides a positive mechanical interlock that is totally resistant to vibration effects when the key structure is biased into load transmitting position by the locking spring 17.

The procedure for mounting the side frame key assembly in installed position is shown by the use of phantom lines in FIG. 1. The bottom key 19 is inserted through the key opening 13 from the bearing side starting with the key directed almost vertically and gradually rotating the key as the lever portion is progressively fed into and through the opening. The top key 18 is fed into place from the inside of the side frame and is seated in the interlock pocket 19? of the bottom key while it rests on the horizontal base 14 of the side frame. Thereafter, the arms 22, 23 of the locking spring are wedged between the base and the beveled underface of the lever portion 19L to tilt the two-piece key structure into contact above and below the key opening. The locking spring is then driven into place with a hammer until the detent portions 22D, 23D engage in the socket 24 and the bolt hole 15, as previously described.

It should be noted that in the preferred embodiment disclosed, the bottom key is inserted from the outside or roller bearing unit side of the side frame wall rather than from the inside. It is contemplated that a twopiece structure could utilize a bottom key inserted from the inside but the clearance requirements would require reduction in the size of the vertical shoulder and reduction in the thickness of the upper corner region of the retainer portion. Such reductions would weaken the cross-sectional strength of the retainer section and would weaken the area where the top key interlocks with the bottom key.

One of the unique advantages of the two-piece angular key structure as shown in the drawings is that the interlock between the top key and the bottom key is effective, even in the absence of the locking spring, to retain the assembly in operative position; thus, if through inadvertence the locking spring is lost or misplaced or improperly applied, the assembly will remain in place and will not be dislodged by vibration effects. No prior one-piece key can remain in place unless its locking device is in placev A modified embodiment having a two-piece angular key structure as shown in FIGS. 4 and 5 is similar to the embodiment of FIGS. 1 to 3 and, in addition, includes additional interlock portions for enhancing the performance of the key assembly under all types of variances at the region of the key opening.

The top key 18 in the embodiment of FIGS. 4 and 5 is shown to have a vertical rear face ISRF, a concave underface 18UF and a depending frontal hook 18FH. Correspondingly, the bottom key 19 in the embodiment of FIGS. 4 and 5 is shown to include a fore and aft slot 19FA that opens centrally through the main wall portion 19M that underlies the interlock pocket 19F. The main wall portion 19M is of reduced thickness and has a flat underface 19FU to provide clearance for establishing a vertical interlock with the frontal hook ISFH which is inserted downwardly and then forwardly through the fore and aft slot 19FA. Finally, the retainer portion 19R of the bottom keying means 19 includes a central return hook portion 19RI-I that extends beyond the vertical plane of the inwardly facing shoulders 19] to establish a vertical interlock beneath the side frame base 14.

The return hook 19RI-I prevents the bottom keying means 19 from nosing up under any conditions while allowing the fulcrum action that distributes load forces both below and above the key opening 13.

The hook portion 18FH retains the top keying means 18 against nosing up so that the assembly remains intact and in constant contact with both the top corner and bottom corner portions that border the key open- A one-piece angular key embodiment is shown in FIG. 6 wherein the top keying means 18 is integrally connected with the bottom keying means 19 through a horizontal main wall that comprises the lever portion 19L.

The bottom key includes a pair of depending lateral flanges 19F which are substantially shorter than in the two-piece form in order to permit the one-piece structure to be inserted through the key opening from the rear. The top key is comprised of a pair of upstanding lateral flanges ISFL, coplanar with the flanges 19F. and a main vertical cross wall 18M.

The rear portion of the key is similar to the other embodiments and cooperates with the spring 17 in the same fashion as previously described. In the absence of the spring, the onepiece key embodiment is readily subject to loss.

Thus, while preferred constructional features of the invention are embodied in the structure illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

What is claimed is:

l. A side frame key assembly for preventing accidental escape of a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame having a vertical side wall having a horizontal base portion projecting away from the roller bearing unit, said vertical side wall having a generally rectangular key opening facing a lower peripheral region of the roller bearing unit, the key opening bordered by a bottom corner portion and a top corner portion of the side wall, said key assembly comprising angular keying structure, freely movable in the key opening and having bottom keying means to fulcrum against said bottom corner portion and top keying means for abutment against said top corner portion, said bottom keying means having an inwardly projecting lever portion overlying said base portion and an outwardly projecting retainer portion bordering the lower peripheral region of the roller bearing unit, and locking spring means releasably reacting between said base portion and said bottom keying means to bias said bottom keying means and top keying means, respectively, into constant engagement with said bottom corner portion and top corner portion.

2. A side frame key assembly as defined in claim 1 wherein said bottom keying means and said top keying means are separate pieces, one of said keying means having a pocket opening towards the other keying means to receive a portion thereof in interlocked relation, said spring means normally maintaining such interlocked relationship between said top and bottom keying means.

3. The side frame key assembly as defined in claim 1 wherein said base portion includes a hole defining an upwardly facing socket, said lever portion has a downwardly open socket in general alignment with the hole, and the locking spring is in the form of a folded leaf spring having generally parallel arms connected by a bowed head and disposed between said lever portion and said base portion, each of said arms having means to interlock with a separate one of said sockets to retain the keying means in assembled position.

4. A side frame key assembly as defined in claim 3 wherein said lever portion has a beveled underface and depending side flanges leading rearwardly from the socket thereof to define a guide pocket that facilitates insertion and removal of the arms of the locking spring between said lever portion and said base portion.

5. A side frame key assembly as defined in claim 1 wherein said key structure is one-piece, with the top keying means 18 being integrally connected with the bottom keying means through a horizontal main wall that comprises the lever portion.

6. The side frame key as defined in claim 5 wherein said base portion includes a hole defining an upwardly facing socket, said lever portion has a downwardly open socket in general alignment with the hole, and the locking spring is in the form of a folded leaf spring having generally parallel arms connected by a bowed head and disposed between said lever portion and said base portion, each of said arms having means to interlock with a separate one of said sockets to retain the keying means in assembled position. 

1. A side frame key assembly for preventing accidental escape of a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame having a vertical side wall having a horizontal base portion projecting away from the roller bearing unit, said vertical side wall having a generally rectangular key opening facing a lower peripheral region of the roller bearing unit, the key opening bordered by a bottom corner portion and a top corner portion of the side wall, said key assembly comprising angular keying structure, freely movable in the key opening and having bottom keying means to fulcrum against said bottom corner portion and top keying means for abutment against said top corner portion, said bottom keying means having an inwardly projecting lever portion overlying said base portion and an outwardly projecting retainer portion bordering the lower peripheral region of the roller bearing unit, and locking spring means releasably reacting between said base portion and said bottom keying means to bias said bottom keying means and top keying means, respectively, into constant engagement with said bottom corner portion and top corner portion.
 2. A side frame key assembly as defined in claim 1 wherein said bottom keying means and said top keying means are separate pieces, one of said keying means having a pocket opening towards the other keying means to receive a portion thereof in interlocked relation, said spring means normally maintaining such interlocked relationship between said top and bottom keying means.
 3. The side frame key assembly as defined in claim 1 wherein said base portion includes a hole defining an upwardly facing socket, said lever portion has a downwardly open socket in general alignment with the hole, and the locking spring is in the form of a folded leaf spring having generally parallel arms connected by a bowed head and disposed between said lever portion and said base portion, each of said arms having means to interlock with a separate one of said sockets to retain the keying means in assembled position.
 4. A side frame key assembly as defined in claim 3 wherein said lever portion has a beveled underface and depending side flanges leading rearwardly from the socket thereof to define a guide pocket that facilitates insertion and removal of the arms of the locking spring between said lever portion and said base portion.
 5. A side frame key assembly as defined in claim 1 wherein said key structure is one-piece, with the top keying means 18 being integrally connected with the bottom keying means through a horizontal main wall that comprises the lever portion.
 6. The side frame key as defined in claim 5 wherein said base portion includes a hole defining an upwardly facing socket, said lever portion has a downwardly open socket in general alignment with the hole, and the locking spring is in the form of a folded leaf spring having generally parallel arms connected by a bowed head and disposed between said lever portion and said base portion, each of said arms having means to interlock with a separate one of said sockets to retain the keying means in assembled position. 